This puzzle:

Notepad: When this puzzle is finished, 12 special squares, along with the shaded squares, will create an image of 56-Down. The 12 squares corresponding to the "reflection" of the special squares, when read clockwise from top left, will spell an alternative name for 56-Down.

JimH notes: I've highlighted the "reflection" squares. They spell out SHIP OF DREAMS. This titanic puzzle stretches several conventions. It's the first Shortz-era grid with up-down mirror symmetry. It is by far the widest. It's even bigger than Kevin's previous huge rectangle. It's not a size record, though, falling nearly 100 squares short of the seven 25x25 Millennium puzzles from 1999. (Here's one.)

I claim this is the world's first cubist crossword. There's the profile view of the ship and its reflection you have to draw yourself and, just maybe, if you squint at the arrangement of black squares, a top view of a ship sailing west. Do you see it? Also, GRID IRON is a great title for a puzzle that looks like a football field but isn't. The constructor tells the story of how he made this puzzle here on Quora.